This invention concerns pumps and more particularly diaphragm pumps utilized to circulate liquids containing a relatively large percentage of solid materials.
In many applications, it is necessary to cause pumping circulation of liquids containing solid materials, which solid materials may include relatively large particles. Such applications include the pumping of slurry in industrial processing plants, contaminated water in sewage treatment facilities, and water-manure mixture in manure flushing systems.
The relatively large quantity of solid material has a great tendency to clog conventional pumps either due to accumulation of solids in the valving openings and ports, or in the clearance spaces between the moving valve parts, and other pump components.
Another problem is encountered in sedimentation or settling out of the solids in the pumping chamber which may lead to ultimate clogging of the pumping action, requiring clean out, increasing the maintenance requirements of the particular installation and the downtime of the system.
Pump configurations which involve close running clearances between the moving parts, restrictions in the flow path through the pump valving chamber and which produce stagnation in the pumping chamber, renders such design susceptible to clogging and malfunction when applied or utilized for such applications.
Accordingly, it is an object of the present invention to provide a pump which is particularly adapted to the pumping of liquids containing a large quantity of solid materials without clogging or other malfunction due to the presence of solids in the pumped liquid.
It is a further object of the present invention to provide such a pump which operates in a highly reliable manner when pumping such liquids.
It is still another object of the present invention to provide such a pump without such flow restrictions or tight running clearances of components and in which stagnation in the flow pattern at locations which would cause malfunction are substantially eliminated.
It is yet another object of the present invention to provide a pump which is simple in configuration and which may be manufactured at relatively low cost and operate in a highly reliable manner in the environment.